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3 years ago

What element forms an ion with an electronic configuration of [kr] and a –2 charge?

2 answers:

8 0

Must be Selenium (Se). It is two space away from Kr, which means that it needs two extra electron to be like a noble gas, Kr.

nekit [7.7K]3 years ago

6 0

Must be Selenium (Se). It is two space away from Kr, which means that it needs two extra electron to be like a noble gas, Kr.

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An aqueous KNO3 solution is made using 76.6 g of KNO3 diluted to a total solution volume of 1.84 L. (Assume a density of 1.05 g/

defon

Answer:

The answer to your question is Molarity = 0.41

Explanation:

Data

mass of KNO₃ = 76.6 g

volume = 1.84 l

density = 1.05 g/ml

Process

1.- Calculate the molecular mass of KNO₃

molecular mass = 39 + 14 + (16 x 3) = 101 g

2.- Calculate the number of moles

101 g of KNO₃ --------------- 1 mol

76.6 g of KNO₃ ------------ x

x = (76.6 x 1) / 101

x = 0.76 moles

3.- Calculate molarity

Molarity = $\frac{number of moles}{volume}$

Substitution

Molarity = $\frac{0.76}{1.84}$

Result

Molarity = 0.41

7 0

3 years ago

Magnesium hydroxide is only very slightly soluble in water. The reaction by which it goes into solution is: Mg(OH) 2 (s) rightle

prohojiy [21]

Answer:

there will a definite decrease in solute solution

Explanation:

acid reaction acting upon negative charge.

3 0

2 years ago

Magnesium reacts with Oxygen gas forming Magnesium oxide as shown;

LuckyWell [14K]

Molar mass:

O2 = 16 x 2 = 32.0 g/mol Mg = 24 g/mol

2 Mg(s) + O2(g) --->2 MgO(s)

2 x 24.0 g Mg -------------> 32 g O2
5.00 g Mg -----------------> ( mass of O2)

mass of O2 = 5.00 x 32 / 2 x 24.0

mass of O2 = 160 / 48

= 3.33 g of O2

hope this helps!

5 0

3 years ago

Mixtures of benzene and cyclohexane exhibit ideal behavior. A solution was created containing 1.5 moles of liquid benzene and 2.

goblinko [34]

Answer:

Vapour pressure of cyclohexane at 50°C is 490torr

Vapour pressure of benzene at 50°C is 90torr

Explanation:

Using Raoult's law, pressure of a solution is defined by the sum of the product sbetween mole fraction of both solvents and pressure of pure solvents.

$P_{solution} = X_{A}P^0_{A}+X_{B}P^0_{B}$